Hi, I am one the maintainers of Ruby in Debian, thanks a lot for adding multiarch support.

While preparing packages for Ruby 2.0, I found two issues:

1) On a x86_64 Debian system with Linux kernel, Ruby will say that the architecture is "x86_64-linux", but the standard architecture name for such a system, as used in multiarch-enabled packages, is "x86_64-linux-gnu". In order to not break other systems, I suggest adding a --with-multiarchname argument to ./configure so that the Debian package can pass in the appropriate architecture name during ./configure stage.

2) the pkg-config data also has to be installed inside multiarch paths.